On Albumo I got my account deleted back in Feb by simple email request. They never sent me even a courtesy reply, but on looking a few days after the email was sent, all the images were gone and I could no longer log in.

On subsequent posts regarding Albumo though, some say they are completely ignored in making such requests, so good luck there. Perhaps there is an exodus in progress and they are trying to put the brakes on.  You can delete one photo per day there - if you have a large batch this will take ages. Just go to the image as if you were editing keywords, and there should be a delete option there.

Just be polite in your email - I just said I no longer had time to maintain or upload.

Can't advise on SV. Much luck to you.

To delete pics on SV
Top right corner of pic  their is an X that is  delete